Question

在我的Dart程序中，我正在使用相机：

...    
final File imageProduct =  await ImagePicker.pickImage(source: ImageSource.camera, maxHeight: 1024, maxWidth: 1024);
...

在以前的版本中，它运行良好，现在，在Flutter升级（v1.7.8 + hotfix.3）之后，显示了相机界面，我可以拍摄照片，之后出现错误：

W/Binder  ( 7331): Caught a RuntimeException from the binder stub implementation.
W/Binder  ( 7331): java.lang.RuntimeException: Methods marked with @UiThread must be executed on the main thread. Current thread: Binder:7331_4

在Flutter中，异步函数在主线程中执行，所以我真的不明白可能是什么问题。我找不到在主线程中强制执行的明确方法。

可能是解决方案。

谢谢。

完成

如果我更改代码：

File imageProduct;
try {
  imageProduct = await ImagePicker.pickImage(
      source: ImageSource.camera, maxHeight: 1024, maxWidth: 1024);
}
catch (err) {
  print('>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> $err');
}

不显示摄像头界面，消息变为：

E/MethodChannel#plugins.flutter.io/image_picker( 8509): Failed to handle method call
E/MethodChannel#plugins.flutter.io/image_picker( 8509): java.lang.IllegalStateException: Reply already submitted
E/MethodChannel#plugins.flutter.io/image_picker( 8509):     at  io.flutter.embedding.engine.dart.DartMessenger$Reply.reply(DartMessenger.java:135)

更多代码（代码是从一个大模块中提取并简化的）：

class _BarcodeHomePageState extends State<BarcodeHomePage> {
String _filename;
String _stareprogram = 'No image captured';

  /* ---------------------------------------------------------------------------
  *  capture imagine  + resize it
  --------------------------------------------------------------------------- */
  Future takeImage(String smode) async {
    await getImage(smode);
    String fname = '$_myExternalDirectory/XYZ/' + _filename + '.jpg';
    if (_filename != null) {
      if (FileSystemEntity.typeSync(fname) != FileSystemEntityType.notFound) {
          await compute(resizeImage, fname).then((_){refreshlist(fname);});
        }
    }
  }

  Future<void> getImage(String smode) async {

    String _filename = '001';

    /* capture picture */
    final File imageProduct =  await ImagePicker.pickImage(source: ImageSource.camera, maxHeight: 1024, maxWidth: 1024);

    if (imageProduct != null) {
      String extJpg = '$_myExternalDirectory/XYZ/' + _filename + '.jpg';
      await imageProduct.copy(extJpg)
          .then((_) { print('>>>>>>>>> Image copied ' + extJpg + ' ...'); })
          .catchError((e) { print('>>>>>>>> Image couldn''t be copied: ' + e.toString()); });

      File imf = new File(extJpg);

      Image newimg = Image.memory(Uint8List.fromList(imf.readAsBytesSync()));

      _listContent.add(new bcImage(_nrord.toString().padLeft(2, '0'),
                                   extJpg,
                                   newimg, true));

      _showSnackBar('New image added');

      /* Refresh stare */
      setState(() {
      });
    }
    else {
      setState(() {
        if (_listContent.isEmpty) {
          _stareprogram = 'No image captured';
        }
      });
    }
  }
  ...
}

class bcImage {
  String nrord;
  String filename;
  Image image;
  bool waiting;

  bcImage(this.nrord, this.filename, this.image, this.waiting);

}

在Dart中的主线程中强制执行

完成

0 个答案: